>I think we should have a menu option (or some other way) to specify whether we want to Extend the parents behavior or Override it.

Nah, as well as the "Where will the parent code fire" issue, there's also how do you get the return value? Anytime I want to "Extend" code I need to know what teh code returned, without DoDefault(), you can't. THe other half of the time I'd use "Extend" is to intercept parameters in the subclass method, change or add to them or something like that, and then let the parent class do its regular thing.

Using "Extend" would only remove a couple of lines of code will makeing a maitence hassle out of the rest.